There are no other SPI chips on that bus. Since the AD5206 is permanently a slave on the SPI bus I would think it would not try to drive the line.
On Tuesday, March 22, 2016 at 10:55:49 AM UTC-4, Harvey White wrote: > > On Tue, 22 Mar 2016 05:47:19 -0700 (PDT), you wrote: > > >I've been building a custom cape for a robotics project and one of the > >chips I'm using is controlled via SPI. I've used an oscilloscope to > >validate that the SPI is working as expected. However, two days ago I > >noticed that the chip stopped responding and after scoping the SPI signal > I > >can see that the BBB is sending the SPI data pulses at 1.8v. The SPI > >signal is still happening... and the clock signal is still at 3.3v. It's > >just the SPI data line that is only peaking at 1.8v. > > > Had a chip (Epson S1D13781) with an SPI interface. Had a similar > problem when sharing the SPI interface with another chip. Bottom line > was that, unlike the standard SPI chips where the chip gets completely > off line when not selected, this chip *always* (the Epson) drives MISO > line low. > > I was getting about 1.8 volts or so maximum voltage out of the > paralleled chip because it was trying to pull up a driver that was > stuck at zero. > > Not sure that you have exactly the same problem, but is the chip > you're driving somehow trying to drive this line (and shouldn't)? > > Harvey > > > > >So, I'm wondering if I've done something bad to my BBB or if I've somehow > >triggered a feature that I don't know about yet. I'm attaching a photo > of > >the oscilloscope screen that shows the issue. > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
